Cell-based assays have been used extensively for research and clinical applications. The most commonly used procedure involves the plating, into welled dishes or multi-well plates, of single cell or multi-cell suspensions in liquid or semi-solid nutrient medium, supplemented with the appropriate combinations of ingredients that support the proliferation and, sometimes, differentiation of individual cells. Well dishes and multi-well plates are used for handling a multitude of liquid samples in both chemical and biological studies in fields such as gene sequencing, combinatorial chemistry, drug discovery and proteomics.
Automation of cell-based assays or other assays performed in culture vessels would provide a great improvement to the field and enable high-throughput screening not currently possible with manual assay methods. Key challenges that need to be overcome to facilitate automation of these assays are the development of specific labelling methods and the removal of the optical interference that is a result of meniscus formation where the liquid medium meets the assay dish wall.
U.S. Patent Application publication no. 2007/0274871 describes a well plate of unitary construction comprising a first part of interconnected tubes that define the side walls of each well and a second part defining the wall bases. The hydrophobicity of the first part is selected to have a surface energy that provides a static contact angle of approximately 90 degrees to inhibit meniscus formation.